These pots are made with stoneware clay that has been fired to 1200c in my kiln. They can be washed in a dish-washer, but be aware that hand-made pots are inherently less durable than mass-produced ware, so care should be taken to avoid chipping rims and handles.
Microwave use is not recommended, as the pieces can become too hot to handle.
Thermal shock can occur when pottery is exposed to very rapid and extreme temperature changes, and can result in cracking and shattering. To avoid this, always warm large mugs with a little hot water before filling; allow freshly boiled water to cool a little; never put a plate or bowl direct from the fridge into a microwave or hot oven; never put a hot dish into cold water.